Our world has been running on fossil fuels (coal and petroleum) for over two hundred years, and is fast using these fuels up. Since it takes millions of years for these fuels to form, the need for an alternate source of energy is growing more and more urgent. The burning of fossil fuels has also been a major contributor to pollution and a possible cause of global warming.
Wind, water, geothermal and tidal energy sources have all been developed but they are limited to specific places. Fission has been developed as well, but has met sturdy resistance from environmental action groups. Fusion energy has yet to live up to its promise. Solar energy via photovoltaic cells has also been developed but these use less than 15% of the available energy and are not yet cost efficient.
Fuel cells, which produce energy by recombining oxygen and hydrogen to generate electricity, have reached 70 to 80 percent efficiency and, since they produce only water, are non-polluting and do not contribute to the greenhouse effect. Until now, the main source of hydrogen for such systems has been through the electrolysis of water. Because energy is required for the electrolysis process, and because in any system some energy is lost to entropy, this process has been inefficient. Many elaborate methods have been designed to reduce the amount of energy needed to split water. Because these either have not worked, or have been very expensive or inefficient processes, it has not been practical to scale up any of these methods for commercial use.
It has been known for over 100 years that hydrogen and oxygen gas may be generated by the electrolysis of water. Electrolysis utilizes electrical power to create a current between an anode and cathode, thereby breaking water into its constituent components, hydrogen and oxygen. Of course, this process has the potential to be particularly important in view of the concern associated with access to hydrocarbons in politically unstable countries. As is well known to those skilled in the art, hydrogen is a clean, plentiful and readily usable fuel. Needless to say, an efficient and economical method of producing hydrogen from readily available materials such as water could have significant value, especially in countries that have few hydrocarbon deposits. Consequently, there is a growing interest in developing new techniques for the efficient production of molecular hydrogen.
In order to reduce the amount of electrical energy necessary to sunder the hydrogen-oxygen bond in water, solar energy is being explored as an energy source. One approach which has been actively explored involves chemical processes which resemble photosynthesis in order to convert water and air into combustible hydrocarbons. Another approach, which is the approach taken by the instant invention, is to accomplish production of hydrogen gas by using sunlight to effect electrolysis of water. Generally, the emphasis with electrolysis has been to use some type of exotic solid state photoelectric cell to generate current and release hydrogen and oxygen. To date, the solid state photoelectric approaches have not proven economically successful.
In 1905, Albert Einstein explained the photoelectric effect using the quantum hypothesis. The photoelectric effect involves the ejection of electrons from a metal surface by light in a vacuum tube. Einstein developed the equation for the energy of these electrons in 1906. The equation is:E=hυ−WThis equation means that the energy (E) of the electrons is equal to Plank's constant (h), multiplied by the frequency of the light (υ), minus the work function (W) of the metal.
For the energy of the electrons to equal that needed for the electrolysis of water, the frequency of light must be in the range of high frequency ultraviolet. Thus, solar energy has heretofore had only limited use in producing hydrogen.
Thus, there exists a need for a method and apparatus that provides efficient electrolysis of water into its constituent elements. Accordingly, it should now be recognized, as was recognized by the present inventors, that there exists, and has existed for some time, a very real need for an invention that would address and solve the above-described problems.
Before proceeding to a description of the present invention, however, it should be noted and remembered that the description of the invention which follows, together with the accompanying drawings, should not be construed as limiting the invention to the examples (or preferred embodiments) shown and described. This is so because those skilled in the art to which the invention pertains will be able to devise other forms of this invention within the ambit of the appended claims.